1. Field of Invention
This invention relates broadly to the field of remote-controlled models, and more specifically to an improved method and apparatus for counting the number of laps completed by radio-controlled models during racing competition.
2. Summary of Prior Art
Radio-controlled model racing is a popular hobby sanctioned by Radio Operated Auto Racing Inc., among other rulemaking bodies. Competition occurs not only between model cars but also model aircraft, boats, etc. Races are generally conducted on a closed-circuit racecourse and require each competing model to complete as many laps as possible within a given time period; the winner completing the largest number of laps in that time. Thus, accurate means of counting the number of laps completed by each model car, boat, etc. is necessary in determining the winner of such a competition.
Each model is controlled in terms of steering, speed, and direction by radio-frequency signals of predetermined frequency generated by a hand-held remote-control transmitter. Each model carries on-board signal receiving apparatus that utilizes the control signals of the frequency assigned to it to cause the model to respond as directed by the "driver."
Prior art lap counters detect the passage by the model of a predetermined spot on the racecourse by detecting the presence of a specific radio-frequency signal emanating from each model. Such prior art lap counters require separate signal-generating apparatus aboard each competing model. The apparatus generates a signal of a frequency unique to each competing model, that is received by the prior art lap counter, allowing the counter to register the passage of the model and to count the number of times each model passes the counter.
The present invention eliminates the need for the individual models to carry on-board lap-counting signal generation apparatus. It has been determined that the control signal receiving apparatus, necessarily present in a radio-control model, spontaneously generates a spurious radio-frequency electromagnetic signal of a frequency that is unique to, and characteristic of each competing model. This spurious signal's strength is within limits set by the F.C.C. The present invention is a means by which this unique, characteristic spurious signal can be detected by a lap counter, eliminating the need for a separate lap-counting signal-generating apparatus aboard the model.